Lesson 1 of 6
Lesson 1 — What Actually Is 'The Cloud'?
Spoiler: it's someone else's computer — thousands of them, in a warehouse, rented by the second.
Learn it
The cloud is a huge collection of computers (servers) in buildings called data centres, which you rent over the internet.
Instead of buying a server, you rent computing power, storage and services and pay only for what you use.
Because the provider owns the hardware, you can get 1 server or 1,000 servers in minutes.
Key terms
- Data centre
- A building full of racked servers, storage, networking, power and cooling.
- Region
- A geographic location containing multiple cloud data centres.
- Availability zone
- An isolated data centre within a region, with its own power and network.
- Elasticity
- Adding or removing resources automatically as demand changes.
- Pay-as-you-go
- Being billed per second/GB used rather than buying hardware upfront.
Follow a video from click to screen
You press play on a streaming app in Malta at 20:00 on a Friday.
- 1Step 1: Your request hits a nearby edge server (CDN) — a cached copy of the video, kept close to reduce latency.
- 2Step 2: If the file isn't cached, the edge fetches it from object storage in the nearest region.
- 3Step 3: Auto-scaling notices Friday-night demand and launches extra streaming servers within seconds.
- 4Step 4: When demand drops at 02:00 the servers are terminated — and the bill stops with them.
Renting a server in one command
bash# Launch a small Linux VM for one hour of work
aws ec2 run-instances \
--image-id ami-0abcdef1234567890 \
--instance-type t3.micro \
--count 1
# ...later, stop paying
aws ec2 terminate-instances --instance-ids i-0123456789abcdef0No purchase order, no delivery, no rack. One API call creates the machine, another destroys it, and you pay for the minutes in between.
Try it
True or false: cloud myths
The cloud has no physical location.
Elasticity means resources can grow and shrink automatically.
Public cloud means your data is visible to the public.
Availability zones protect against a single data centre failing.
Challenge
Your school wants to host its exam-results website. Traffic is near zero all year, then 12,000 students hit it in one hour on results day. Explain why cloud hosting suits this better than one school server, and name two risks.
Pick whichever way suits you — every mode earns the same bonus XP.
Write at least 40 more characters to submit.
Mark your own work
Guided walkthrough — 0/4 clues revealed
- Clue 1 locked — reveal it only if you get stuck.
- Clue 2 locked — reveal it only if you get stuck.
- Clue 3 locked — reveal it only if you get stuck.
- Clue 4 locked — reveal it only if you get stuck.
Each clue costs 4 XP (never below 18 XP). You'd earn 35 XP right now.